Physiographic features

This woodland community occurs on the cool, moist back slopes of mountains at higer elevations and in drainageways at lower elevations. Slopes range from 30 to 75 percent. Elevations range from 6900 to 9710 feet.

Table 2. Representative physiographic features

Climatic features

The primary air masses affecting the Spring Mountains are cold maritime polar air from the Gulf of Alaska and warmer, moist maritime subtropical air from lower latitudes. Occasionally there are invasions of cold continental polar air from northern Canada or the Rocky Mountains. Precipitation in the area results primarily from the passage of cyclones with associated fronts during fall, winter and spring; from closed cyclones in late winter and spring; and from the flow of moist tropical air from the southeast to the southwest quadrant in the summer.

The mean annual precipitation is about 18 to 24 inches. Mean annual air temperature is 41 to 45 degrees F. The average growing season is about 60 to 95 days. There is no available climate station available for this site.

Snow Course, Spring Mountains, Nevada. Average snow depth and snow water equivalent from 1971 to 2000 at March 1 and April 1 of each year.

Kyle Canyon. (Elevation 8200 feet.) March 1. 36 inch snow depth, 10.9 inches of water equivalent. April 1. 31 inch snow depth, 11.7 inches of water equivalent.

Rainbow Canyon #2 (Elevation 8100 feet) March 1. 44 inch snow depth, 13.8 inches of water equivalent. April 1. 46 inch snow depth, 16.7 inches of water equivalent.

Lee Canyon #2. (Elevation 9000 feet) March 1. 35 inch snow depth, 10.6 inches of water equivalent. April 1. 31 inch snow depth, 11.1 inches of water equivalent.

Lee Canyon #3. (Elevation 8500 feet) March 1. 28 inch snow depth, 8.5 inches of water equivalent. April 1. 24 inch snow depth, 9.1 inches of water equivalent.

Table 3. Representative climatic features

Influencing water features

There are no influenceing water features associated with this site.

Soil features

Soils associated with this site are generally moderately deep to deep and well drained. They have formed in colluvium from limestone and dolomite. There may be a 1 to 4 inch thick layer of forest litter in various stages of decomposition at the surface. This layer of organic matter reduces moisture loss due to evaporation. Approximately 10 to 30 percent of the surface is covered with a needle and twig organic layer. The soil temperature is frigid. Soils are usually moist in late winter and spring, and periodically moist in the upper part following summer thunderstorms. Soil series associated with this site include Robbersfire and Devilsthumb.

Table 4. Representative soil features

Animal community

Livestock Interpretations:
This site is suited to cattle and sheep grazing during the spring and fall. Livestock will often concentrate on this site taking advantage of the shade and shelter offered by the tree overstory. Many areas are not used because of steep slopes and the lack of adequate water. Attentive grazing management is required due to steep slopes and erosion hazards. Harvesting trees under a sound management program can open up the tree canopy to allow increased production of understory species desirable for grazing. Stands dominated by white fir seldom produce enough forage for domestic livestock grazing except on harvested or open forest sites, or where grasses and sedges dominate the understory.

Stocking rates vary over time depending upon season of use, climate variations, site, and previous and current management goals. A safe starting stocking rate is an estimated stocking rate that is fine tuned by the client by adaptive management through the year and from year to year.

Wildlife Interpretations:
These forests provide abundant browse and cover for large and small wildlife species. Mule deer, elk, and bear often use white fir habitats as either summer or winter range. Mule deer generally eat small amounts of white fir during the spring, fall, and winter, and sometimes larger amounts during the summer. Spring browsing of white fir by deer can be particularly heavy when small white firs are the only green food available; all of the current or previous year's growth may be consumed. Porcupines also feed on the bark of white fir, and may destroy saplings. Rodents feed on the cambial tissue of white fir. During the winter, mice feed on the leaders of small white firs near snow level. In the spring, they feed on seedlings, sometimes destroying a large proportion of the current year's seedlings. Pocket gophers also feed on white fir seedlings in the winter and spring. White fir needles are an important part of the diet of blue grouse. White fir seeds are eaten by several species of small mammals and birds including grouse, chipmunks and mice, flying squirrels, chickadees, crossbills, and Clark's nutcracker. Hollow logs and snags of white fir can be important to various birds and animals for foraging in the interior wood. Because they contain resins, terpenes, and other substances that make the foliage irritating to the digestive tract, most conifers are not particularly palatable to grazing animals. White fir may be slightly palatable to goats. Immature foliage is also consumed by mule deer. White fir seeds are palatable to numerous species of small rodents.

White fir's evergreen foliage provides good hiding cover year-round and is usually continuous from the ground upward on trees less than 8 to 10 inches (20-25 cm) dbh. White fir stands of this nature provide excellent hiding cover for large wildlife species such as deer, elk, and black bear. If enough shrubs are present in the understory to provide adequate hiding cover, mature white fir forests are used by deer during fawning and by elk during calving.

Hydrological functions

Runoff is high. Potential for sheet and rill erosion is moderate to severe depending on slope.

Recreational uses

This site has moderate aesthetic value and provides a variety of recreational opportunities such as hiking, camping, and deer and upland game bird hunting. Steep slopes and the fragile soil-vegetation complex, however, inhibit many other forms of recreation such as the use of off-road vehicles.

Wood products

Principle uses of white fir are poles, fuelwood, and some lumber. The wood produced from this site is generally of poor quality, however, white fir has potential for the production of pulp, possibly boxwood, and other manufactured wood products.
The wood of ponderosa pine is valuable for lumber.

This site is of very low quality for tree production. Site index ranges from less than 20 for white fir and ponderosa pine.

Tree volume for white fir ranges from less than 40 cubic feet per acre for stands averaging 30 to 40 feet in height at 70 years of age.

Fuelwood Production: About 20 to 40 cords per acres for stands averaging 30 to 40 feet in height and 70 years of age. There are about 210,000 British Thermal Units (BTU’s) of heat energy per cubic foot of mixed white fir, limber pine and bristlecone pine wood. Firewood is stacked unit equivalent to 128 cubic feet. Solid wood volume in a cord varies but straight material of even taper will give a solid volume of 80 to 90 cubic feet. Assuming an average of 85 cubic feet of solid wood per cord, there are about 18 million BTU’s of heat value in a cord of wood of mixed white fir, limber pine, and bristlecone pine firewood.

Limits and Considerations
a. Potential for sheet and rill erosion is moderate to severe depending on slope.
b. Severe equipment limitations on steeper slopes.

Essential Requirements
a. Adequately protect from uncontrolled burning to protect woodland resources and reduce potential erosion hazards.
b. Protect soils from accelerated erosion. Use water bars at designed spacing on roads. Follow designed in-sloping, out-sloping or crowning of roads (with necessary ditching and reliable culverts.)

Silvicultural treatments are not reasonably applied on this site due to poor site quality and severe limitation for equipment and tree harvest.

Other products

Although no longer harvested, the oleoresin, or pitch, of ponderosa pine has been a source of turpentine in the past.

Other information

Associated with this ecological site are 14 plant species of concern, 4 of which are endemic to the Spring Mountain National Recreation Area (SMNRA). There are also 10 animal species of concern, 3 which are endemic to the SMNRA.

Table 7. Representative site productivity

Type locality

Other references

Clokey, Ira. 1951. Flora of the Charleston Mountains Clark County, Nevada. University of California Press, Berkeley and Los Angeles.

Fire Effects Information System [Online]http://www.fs.fed.us/feis

Glenne, G. and D. Johnson. 2002. Guide to Species of Concern in the Spring Mountains National Recreation Area, Clark and Nye Counties, Nevada. USFS, Las Vegas, NV.

Lanner, R.M. 1984. Trees of the Great Basin. University of Nevada Press, Reno NV.

Meyer, W.H. 1938. Even-aged stands of Ponderosa Pine. USDA Tech Bull 630.

Nachlinger, J. and G. Reese. 1996. Plant Community Classification of the Spring mountains National Recreation Area, Clark and Nye Counties, Nevada. The Nature Conservancy. Reno, Nevada. III. High conifer forest and Woodland Zone. 8 Abies concolor-Pinus ponderosa var. scopulorum-Cercocarpus ledifolius var intermontanus Series. White fir-ponderosa pine-cuflleaf mountain mahogany Series. Page I-46-47.

USDA. NRCS National Forestry Handbook, Exhibit 637-32. 190-V-NFH, Feb. 2001.

USDA. SCS National Forestry Manual, Table 21 190-V-NFN, Amend. 3, 1983.

Contributors

TJ WOLFE

Approval

Kendra Moseley, 4/26/2024